Image processing apparatus and method

Abstract

By smoothing a full-color image, staircasing of characters even in a gradation image is removed. An area to be smoothed is detected from image data having a plurality of color components, and image data included in the detected area is smoothed in units of color components. Image data which places an importance on resolution is smoothed by increasing the resolution to reproduce smooth characters and figures. Image data which places an importance on gradation characteristic is output without increasing the resolution, thus attaining high-gradation recording. A character or figure is detected from bitmap image data input from external equipment, and is smoothed. In correspondence with the density of the smoothed image data, the pulse width is switched, thereby changing the resolution of image data.

What is claimed is:  
     
         1 . An image processing apparatus characterized by comprising: 
 input means for inputting multi-valued image data having a plurality of color components;    detection means for detecting an area to be smoothed from the multi-valued image data having the plurality of color components; and    smoothing means for smoothing multi-valued image data included in the area detected by said detection means in units of color components.    
     
     
         2 . The apparatus according to  claim 1 , characterized in that said smoothing means further comprises resolution conversion means for generating image data having a resolution twice a resolution of the multi-valued image data having the plurality of color components from the multi-valued image data in the area detected by said detection means.  
     
     
         3 . The apparatus according to  claim 2 , characterized in that said resolution conversion means generates image data having a resolution corresponding to a natural number multiple of the resolution of the multi-valued image data having the plurality of color components from the multi-valued image data in the area detected by said detection means.  
     
     
         4 . The apparatus according to  claim 1 , characterized in that the multi-valued image data having the plurality of color components is full-color image data which is color-separated into yellow, magenta, cyan, and black components.  
     
     
         5 . The apparatus according to  claim 1 , characterized in that the multi-valued image data having the plurality of color components is input from external equipment.  
     
     
         6 . The apparatus according to  claim 1 , characterized by further comprising means for determining a thickness of character and line image portions in an original image, means for determining an edge of a character or line image in the original image, and means for determining saturation of the line image in the original image.  
     
     
         7 . The apparatus according to  claim 2 , characterized in that said resolution conversion means generates image data having a resolution twice the resolution of the multi-valued image data having the plurality of color components by interpolating the resolution of the multi-valued image data.  
     
     
         8 . The apparatus according to  claim 3 , characterized in that said resolution conversion means generates image data having a resolution corresponding to the natural number multiple of the resolution of the multi-valued image data having the plurality of color components by interpolating the resolution of the multi-valued image data.  
     
     
         9 . An image processing method characterized by comprising: 
 the input step of inputting multi-valued image data having a plurality of color components;    the detection step of detecting an area to be smoothed from the multi-valued image data having the plurality of color components; and    the smoothing step of smoothing multi-valued image data included in the area detected in the detection step in units of color components.    
     
     
         10 . The method according to  claim 9 , characterized in that the smoothing step further comprises the resolution conversion step of generating image data having a resolution twice a resolution of the multi-valued image data having the plurality of color components from the multi-valued image data in the area detected in the detection step.  
     
     
         11 . The method according to  claim 10 , characterized in that the resolution conversion step includes the step of generating image data having a resolution corresponding to a natural number multiple of the resolution of the multi-valued image data having the plurality of color components from the multi-valued image data in the area detected in the detection step.  
     
     
         12 . The method according to  claim 9 , characterized in that the multi-valued image data having the plurality of color components is full-color image data which is color-separated into yellow, magenta, cyan, and black components.  
     
     
         13 . The method according to  claim 9 , characterized in that the multi-valued image data having the plurality of color components is input from external equipment.  
     
     
         14 . The method according to  claim 9 , characterized by further comprising the step of determining a thickness of character and line image portions in an original image, the step of determining an edge of a character or line image in the original image, and the step of determining saturation of the line image in the original image.  
     
     
         15 . The method according to  claim 10 , characterized in that the resolution conversion step includes the step of generating image data having a resolution twice the resolution of the multi-valued image data having the plurality of color components by interpolating the resolution of the multi-valued image data.  
     
     
         16 . The method according to  claim 11 , characterized in that the resolution conversion step includes the step of generating image data having a resolution corresponding to the natural number multiple of the resolution of the multi-valued image data having the plurality of color components by interpolating the resolution of the multi-valued image data.  
     
     
         17 . A computer-readable memory which stores a program code of image processing, characterized by comprising: 
 a code of the input step of inputting multi-valued image data having a plurality of color components;    a code of the detection step of detecting an area to be smoothed from the multi-valued image data having the plurality of color components; and    a code of the smoothing step of smoothing multi-valued image data included in the area detected in the detection step in units of color components.    
     
     
         18 . An image processing apparatus characterized by comprising: 
 input means for inputting a command that represents an image;    bitmap data generation means for generating bitmap data on the basis of the command that represents the image; and    attribute generation means for generating attribute information on the basis of an attribute of an object that forms an image, and the bitmap data.    
     
     
         19 . The apparatus according to  claim 18 , characterized in that the attribute information is generated in correspondence with a two-dimensional coordinate position of the bitmap data, and attribute information at an identical coordinate position with the bitmap data is output in synchronism with the bitmap data.  
     
     
         20 . The apparatus according to  claim 18 , characterized by further comprising switching means for switching the number of output lines in correspondence with a thickness of a character/line image in the image.  
     
     
         21 . The apparatus according to  claim 18 , characterized in that the bitmap data is full-color image data which is color-separated into yellow, magenta, cyan, and black components.  
     
     
         22 . The apparatus according to  claim 18 , characterized by further comprising means for determining a thickness of character and line image portions in the image, means for determining an edge of a character or line image in the image, and means for determining saturation of the line image in the image.  
     
     
         23 . The apparatus according to  claim 18 , characterized by further comprising means for generating resolution-improved image data by interpolating a resolution of the bitmap data in accordance with the attribute information.  
     
     
         24 . The apparatus according to  claim 18 , characterized in that the attribute information includes one of information indicating whether data of interest is a vector image area or not, information indicating whether the data of interest is a character area or not, information indicating whether the data of interest is an object boundary portion or not, information of a pixel where the vector image area changes, and information of a pixel which neighbors the pixel where the vector image area changes.  
     
     
         25 . The apparatus according to  claim 18 , characterized in that the bitmap data is smoothed in accordance with the attribute information.  
     
     
         26 . The apparatus according to  claim 18 , characterized in that the number of lines used in image formation is determined and the bitmap data is smoothed in accordance with the attribute information.  
     
     
         27 . An image processing method characterized by comprising: 
 the input step of inputting a command that represents an image;    the bitmap data generation step of generating bitmap data on the basis of the command that represents the image; and    the attribute generation step of generating attribute information on the basis of an attribute of an object that forms an image, and the bitmap data.    
     
     
         28 . The method according to  claim 27 , characterized in that the attribute information is generated in correspondence with a two-dimensional coordinate position of the bitmap data, and attribute information at an identical coordinate position with the bitmap data is output in synchronism with the bitmap data.  
     
     
         29 . The method according to  claim 27 , characterized by further comprising the switching step of switching the number of output lines in correspondence with a thickness of a character/line image in the image.  
     
     
         30 . The method according to  claim 27 , characterized in that the bitmap data is full-color image data which is color-separated into yellow, magenta, cyan, and black components.  
     
     
         31 . The method according to  claim 27 , characterized by further comprising the step of determining a thickness of character and line image portions in the image, the step of determining an edge of a character or line image in the image, and the step of determining saturation of the line image in the image.  
     
     
         32 . The method according to  claim 27 , characterized by further comprising the step of generating resolution-improved image data by interpolating a resolution of the bitmap data in accordance with the attribute information.  
     
     
         33 . The method according to  claim 27 , characterized in that the attribute information includes one of information indicating whether data of interest is a vector image area or not, information indicating whether the data of interest is a character area or not, information indicating whether the data of interest is an object boundary portion or not, information of a pixel where the vector image area changes, and information of a pixel which neighbors the pixel where the vector image area changes.  
     
     
         34 . The method according to  claim 27 , characterized in that the bitmap data is smoothed in accordance with the attribute information.  
     
     
         35 . The method according to  claim 27 , characterized in that the number of lines used in image formation is determined and the bitmap data is smoothed in accordance with the attribute information.  
     
     
         36 . A computer-readable memory which stores a program code of image processing, characterized by comprising: 
 a code of the input step of inputting a command that represents an image;    a code of the bitmap data generation step of generating bitmap data on the basis of the command that represents the image; and    a code of the attribute generation step of generating attribute information on the basis of an attribute of an object that forms an image, and the bitmap data.    
     
     
         37 . An image processing apparatus characterized by comprising: 
 input means for inputting image data having a plurality of color components, obtained by color-separating an image;    detection means for detecting an area to be smoothed from the image data having the plurality of color components;    smoothing means for smoothing the image data having the plurality of color components included in the area detected by said detection means;    output means for outputting a recording signal of a predetermined resolution on the basis of the smoothed image data; and    switching means for switching an output resolution of said output means.    
     
     
         38 . The apparatus according to  claim 37 , characterized in that said output means generates a recording signal, a pulse width of which is modulated on the basis of the smoothed image data and a reference signal, and said switching means switches the output resolution by switching the recording signal.  
     
     
         39 . The apparatus according to  claim 38 , characterized in that said output means modulates the pulse width of the recording signal using at least two reference signals having different periods.  
     
     
         40 . The apparatus according to  claim 39 , characterized in that said switching means selects one of the two reference signals having different periods.  
     
     
         41 . The apparatus according to  claim 37 , characterized in that said smoothing means smoothes bitmap image data at a resolution twice a resolution of the image data in the area detected by said detection means.  
     
     
         42 . The apparatus according to  claim 37 , characterized in that said smoothing means smoothes bitmap image data at a resolution corresponding to a natural number multiple of a resolution of the image data in the area detected by said detection means.  
     
     
         43 . The apparatus according to  claim 37 , characterized in that the image data having the plurality of color components is full-color image data which is color-separated into yellow, magenta, cyan, and black components.  
     
     
         44 . The apparatus according to  claim 37 , characterized in that the image data having the plurality of color components is read from external equipment.  
     
     
         45 . The apparatus according to  claim 41 , characterized in that said smoothing means generates image data having a resolution twice the resolution of the image data having the plurality of color components by interpolating the image data.  
     
     
         46 . The apparatus according to  claim 42 , characterized in that said smoothing means generates image data having a resolution corresponding to the natural number multiple of the resolution of the image data having the plurality of color components by interpolating the image data.  
     
     
         47 . An image processing method characterized by comprising: 
 the input step of inputting image data having a plurality of color components, obtained by color-separating an image;    the detection step of detecting an area to be smoothed from the image data having the plurality of color components;    the smoothing step of smoothing the image data having the plurality of color components included in the area detected in the detection step;    the output step of outputting a recording signal of a predetermined resolution on the basis of the smoothed image data; and    the switching step of switching an output resolution of the output step in correspondence with a characteristic of the smoothed image data.    
     
     
         48 . The method according to  claim 47 , characterized in that the output step includes the step of generating a recording signal, a pulse width of which is modulated on the basis of the smoothed image data and a reference signal, and the switching step includes the step of switching the output resolution by switching the recording signal.  
     
     
         49 . The method according to  claim 48 , characterized in that the output step includes the step of modulating the pulse width of the recording signal using at least two reference signals having different periods.  
     
     
         50 . The method according to  claim 49 , characterized in that the switching step includes the step of selecting one of the two reference signals having different periods.  
     
     
         51 . The method according to  claim 47 , characterized in that the image data having the plurality of color components is full-color image data which is color-separated into yellow, magenta, cyan, and black components.  
     
     
         52 . The method according to  claim 47 , characterized in that the image data having the plurality of color components is read from external equipment.  
     
     
         53 . A computer-readable memory which stores a program code of image processing, characterized by comprising: 
 a code of the input step of inputting image data having a plurality of color components, obtained by color-separating an image;    a code of the detection step of detecting an area to be smoothed from the image data having the plurality of color components;    a code of the smoothing step of smoothing the image data having the plurality of color components included in the area detected in the detection step;    a code of the output step of outputting a recording signal of a predetermined resolution on the basis of the smoothed image data; and    a code of the switching step of switching an output resolution of the output step in correspondence with a characteristic of the smoothed image data.